The fungal cultivar of leaf‐cutter ants produces specific enzymes in response to different plant substrates

Herbivores use symbiotic microbes to help derive energy and nutrients from plant material. Leaf‐cutter ants are a paradigmatic example, cultivating their mutualistic fungus Leucoagaricus gongylophorus on plant biomass that workers forage from a diverse collection of plant species. Here, we investigate the metabolic flexibility of the ants’ fungal cultivar for utilizing different plant biomass. Using feeding experiments and a novel approach in metaproteomics, we examine the enzymatic response of L. gongylophorus to leaves, flowers, oats or a mixture of all three. Across all treatments, our analysis identified and quantified 1766 different fungal proteins, including 161 putative biomass‐degrading enzymes. We found significant differences in the protein profiles in the fungus gardens of subcolonies fed different plant substrates. When provided with leaves or flowers, which contain the majority of their energy as recalcitrant plant polymers, the fungus gardens produced more proteins predicted to break down cellulose: endoglucanase, exoglucanase and β‐glucosidase. Further, the complete metaproteomes for the leaves and flowers treatments were very similar, while the mixed substrate treatment closely resembled the treatment with oats alone. This indicates that when provided a mixture of plant substrates, fungus gardens preferentially break down the simpler, more digestible substrates. This flexible, substrate‐specific enzymatic response of the fungal cultivar allows leaf‐cutter ants to derive energy from a wide range of substrates, which likely contributes to their ability to be dominant generalist herbivores.     

Constructing interpretive ethnicity in between two nations: television and diasporic discourses of identity in Malaysia

This article discusses the interpretation of television in relation to ethnic identity embraced by the female members of Javanese diaspora in Malaysia. The Javanese diaspora in this context refers to the descendants of the colonial Javanese migrants from Indonesia. In contemporary Malaysia, they are considered as Malays, but essentially they retain some cultural identifications of Javanese ethnicity, especially the language. As Malaysia becomes one of the destinations for Indonesian migrant labour and popular culture, the Javanese diaspora are certainly exposed to manifold images of their ethnic origin. Through the audience ethnography in a Javanese community of Selangor, this article reveals that the Malaysian Javanese women negotiate both representative and distant images of Javanese identity on television. Their interpretation of ethnic identity from television represents the notion of ‘interpretive ethnicity’.     

From Community Laywomen to Breast Health Workers: A Pilot Training Model to Implement Clinical Breast Exam Screening in Malawi

Background

Breast cancer burden is high in low-income countries. Inadequate early detection contributes to late diagnosis and increased mortality. We describe the training program for Malawi’s first clinical breast exam (CBE) screening effort.

Methods

Laywomen were recruited as Breast Health Workers (BHWs) with the help of local staff and breast cancer advocates. The four-week training consisted of lectures, online modules, role-playing, case discussions, CBE using simulators and patients, and practice presentations. Ministry of Health trainers taught health communication, promotion, and education skills. Breast cancer survivors shared their experiences. Clinicians taught breast cancer epidemiology, prevention, detection, and clinical care. Clinicians and research staff taught research ethics, informed consent, data collection, and professionalism. Breast cancer knowledge was measured using pre- and post-training surveys. Concordance between BHW and clinician CBE was assessed. Breast cancer talks by BHW were evaluated on a 5-point scale in 22 areas by 3 judges.

Results

We interviewed 12 women, and 4 were selected as BHWs including 1 breast cancer survivor. Training was dynamic with modification based on trainee response and progress. A higher-than-anticipated level of comprehension and interest led to inclusion of additional topics like breast reconstruction. Pre-training knowledge increased from 49% to 91% correct (p<0.0001). Clinician and BHW CBE had 88% concordance (kappa 0.43). The mean rating of BHW educational talks was 4.4 (standard deviation 0.7).

Conclusions

Malawian laywomen successfully completed training and demonstrated competency to conduct CBE and deliver breast cancer educational talks. Knowledge increased after training, and concordance was high between BHW and clinician CBE.     

Incomplete and Aberrant Particles of Actinophage MSP2 from Lysates of Streptomyces venezuelae

Lysates of actinophage MSP2, propagated on Streptomyces venezuelae S13, contain at least 10(11) PFU/ml. During purification by centrifugation methods and by adsorption chromatography, a number of types of aberrant and incomplete phage particles were seen by electron microscopy. Infectious MSP2 had a buoyant density in CsCl of 1.52 g/cm(3) and an absorbance at 260 nm relative to that at 280 nm (A(260)/A(280)) of 1.53. Empty capsids banded at 1.276 g/cm(3) and partially filled capsids banded at 1.351 g/cm(3), and A(260)/A(280) ratios were 0.77 and 1.24, respectively. Two kinds of light capsids found in CsCl fractions of 1.278 g/cm(3) probably include the 1.276 component. Some capsids were joined by tail-like structures. Ghosts and polyheads also were present. Aberrant particles observed by electron microscopy included two-tailed actinophage, phage with abnormal tail positions, and large-headed phage.     

The Incidence of Asbestos Bodies in the Lungs at Random Necropsies in Montreal

The incidence of asbestos bodies in the lungs of adult patients selected at random, who died in four Montreal hospitals, was studied by examining fresh unstained smears of lungs obtained at necropsy. Two techniques were used for preparation of the smears and an arbitrary grading system was developed to estimate the degree of contamination of the lungs by asbestos bodies.Asbestos bodies were present in 48 out of 100 necropsies; they were found in 32 of 56 men (57%) and in 16 of 44 women (34%). Men were more heavily contaminated. The proportion of positive smears depended on the technique used and the amount of lung sampled. No particular association was noted between asbestos bodies in the lungs and the presence of cancer in the 33 patients in this series with malignant disease. The high incidence in this random series suggests that asbestos is a significant air contaminant in Montreal.     

Identification of a slime exopolysaccharide depolymerase in mucoid strains ofPseudomonas aeruginosa

Strains ofPseudomonas aeruginosa recovered from pulmonary infections in cystic fibrosis (CF) patients are often mucoid in appearance owing to the secretion of a viscous slime exopolysaccharide (EPS). Unlike most mucoid isolates, strains WcM#2, P10, and P11 produce mucoid colonies after 24 h of incubation at 37°C, which become nonmucoid upon further incubation; this suggests the presence of a slime-degrading enzyme or depolymerase. Using both qualitative and quantitative assays, the presence of a slime EPS depolymerase was confirmed in each of these three strains as well as in four of four additional mucoid strains. Depolymerase activity was lower but still detectable in four of four nonmucoid strains. Enzyme preparations from strains WcM#2, P10, and P11 were active on most, but not all, slime EPS preparations fromP. aeruginosa strains, as well as sodium alginate; greater activity was observed on substrates after deacetylation. Comparisons are made between the enzyme described in this study and previous reports of slime EPS depolymerase in mucoid strains ofP. aeruginosa.     

Observational methods to measure behaviors of captive cotton‐top tamarins (Saguinus oedipus)

The purpose of this study was to identify efficient sampling methods for establishing accurate activity budgets for zoo animals. Seven cotton‐top tamarins (Saguinus oedipus) from two zoos were videotaped for multiple 90 min sessions, 3 to 4 days per week for 12 weeks. An activity budget was constructed for each animal using a continuous sampling method to analyze 30 hr of video recording of each animal. These master datasets, reflecting actual behavior, were re‐sampled using interval sampling lengths of 0.25, 0.5, 1, 2, 4, 5, 7, 10, 15 and 20 min, and cluster sampling protocols (periodic sessions of continuous sampling) of 10 min×3, 15 min×2, 20 min×1, 15 min×1 and 10 min×1 (min×repetitions/90 min sample period) to construct additional activity budgets for each animal. The Canberra similarity index was used to determine the statistical relationship between these activity budgets and those based on the master datasets. As interval length increased, there was a consequent decrease in the accuracy of the associated activity budgets as compared with the master dataset. No cluster sampling protocols yielded activity budgets as accurate as the four shortest interval lengths, but all cluster sampling protocols were more accurate than the three longest interval lengths. All the tested protocols varied in ability to accurately portray animal behavior. Overall, interval sampling provided superior behavioral representations at lower observer input. Results from this study will potentially facilitate the standardization of behavior monitoring protocols at zoos. Zoo Biol 29:416–431, 2010. © 2009 Wiley‐Liss, Inc.